This invention relates to a lifting device and in particular to a device adapted for lifting curbing sections such as those formed from concrete or cement and utilized adjacent roadways and the like. Such curbing sections are generally lifted into place by a three-man team including two men at the curb section itself and another man operating the lifting device such as a crane, backhoe, or the like from which a cable is attached to the curbing section via loops surrounding a cross-sectional portion thereof.
A number of devices to theoretically improve the lifting of curb sections or similarly shaped heavy articles have been divised and are set forth in the following patents: U.S. Pat. No. 1,888,083 to Holtz issued Nov. 15, 1932; U.S. Pat. No. 2,676,838 to Gardner issued Apr. 27, 1954; U.S. Pat. No. 2,851,300 to Trayer, Jr. issued Sept. 9, 1958; and West German Pat. No. 1,297,313 issued June 12, 1969. These patents illustrate devices while believed to be operational and capable of alleviating one or more of the various problems normally associated with lifting of such heavy devices still do not completely resolve the particular problems normally associated with the lifting of curb sections in a road constructional environment.
The desirable features of a device for lifting, manipulating, and setting curb sections include a structure which substantially directly overlies the top of the curb section such that it can be easily manipulated in place by one person especially in those cases where laterally disposed obstructions exist and, accordingly, holding devices which operate from a side position are not convenient. A further desirable feature of a device of this type is that it operates so as to grasp the curb section on opposed lateral sides thereof rather than either completely encircling or engaging at least a portion of the bottom curb surface. This feature is desirable as the bottom surface of curbing is not always readily accessible (as when repositioning previously positioned curbs) or when removal of the engaging device would be a problem.
These and other objects of the present invention are accomplished by a curb lifter having a frame including a top wall from which a first fixed support downwardly extends at one end thereof, said first support having a first jaw at the lower end thereof with said jaw provided with a substantially planar inner face for contacting one side portion of said curb, a second support downwardly extending from the other end of said top and provided with a second curb side portion contacting jaw at the lower end thereof such that said jaws are normally laterally spaced apart from each other in a relatively open position, said second support pivotally mounted with respect to said top such that its lower end may move towards said first support to a relatively closed second position wherein said jaws grasp said curb, actuation means for moving said second support to said closed position including first and second pairs of inwardly extending and respectively longitudinally spaced rigid lever arms respectively pivotally attached to said first and second supports and pivotally connected to each other by a rigid longitudinally extending generally centrally disposed main shaft, said lever pairs generally horizontally disposed in said open position and a lifting cable having its lower end extending downwardly through said top and in turn connected to said main shaft wherein upward movement of said cable forces the inner ends of said lever arms upwardly thereby shortening the distance between said lever arm pair support connections so as to in turn force said second support and the second jaw into said second closed grasping position.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.